Public transport is great in most big cities I've been to. Vienna had an especially great system of subways. But public transport outside of major cities is just inefficient. I've wasted years of my life waiting on busses and trains already.

Personal flying 'cars' won't be a likely solution, simply because you need to meet much harder criteria to be allowed to fly than to drive. Accidents will more often be lethal, and as Gawain pointed out, the danger to the surrounding people is pretty high.